[3.13] gh-138966: Add description for gi_suspended attribute (GH-139008) (GH-139019)

gh-138966: Add description for `gi_suspended` attribute (GH-139008)
(cherry picked from commit c025576)

Co-authored-by: Donghoon Nam <[email protected]>

Author: miss-islington

Doc/library/inspect.rst

@@ -222,6 +222,9 @@ attributes (see :ref:`import-mod-attrs` for module attributes):
 +-----------------+-------------------+---------------------------+
 |                 | gi_running        | is the generator running? |
 +-----------------+-------------------+---------------------------+
+|                 | gi_suspended      | is the generator          |
+|                 |                   | suspended?                |
++-----------------+-------------------+---------------------------+
 |                 | gi_code           | code                      |
 +-----------------+-------------------+---------------------------+
 |                 | gi_yieldfrom      | object being iterated by  |